Bismuth disalicylate and process of making same.



; rinirnn s rapes PATENT enric I BRUNO RICHARD SEIFERT, F RADEBEUL, NEAR DRESDEN, GERMANY,

ASSIGNOR TO CHEMISCHE FABRlK VON HEYDEN AKTIENGESELL- 'SCHAFT, OF RADEBEUL, NEAR DRESDEN, GERMANY.-

BlSlVlUTl-l DESAMWIE AWE WEDGE-1S8 3F MAKlNC-Ii SSAMEIQ.

Specification OfLElitelS Eatent.

Patented Jan. 9, 1908.

Application filed October 10. 1905. Serial No 282,150-

, vented a new and useful lvlanui'acture of Bismuth Disalicylate, of which the following is a specification. i Under the name of bismuth salicylate two preparations are to be had in the market. One of them, called bismuth subsalicylate, answers to the chemical formula 0 =Bi- OOC.CH,OH. This salt may be best and simply called bismuth monosalicylatc. The other one, the so-called neutral bismuth salicylate, is said to correspond with the formula of the neutral salt Bil- (OOC ILOlD It consequently would have to be considered as bismuth trisalicylate. This product of the market is, however, by no means a chemical individual, but a mixture, and consists principally of much free salicylic acid and bismuth salicylate. 'llhicbault (Ulz emilccr-Zett u ng, 1901, Repertorimn ll, page obtained a salt with oneand one-half molecules of salicylic acid to one atom of bismuth oocoaton Bi i cocoa-non 1, page 162) has described the manufacture of a bismuth trisalicylate; but his product is no bismuth salicylate at all. It contains only free salicylic acid, for all salicylic acid contained in this product can be extracted by cold ether or alcohol. It is obvious that when proceeding according to Causse bismuth salicylate as iinal substance cannot be obtained at all, for Causses reaction takes place in the presence of a solution of ammonium chlorid, and I have found that a solution of ammonium chlorid decomposes bismuth salicylatc into bismuth oxychlorid and ammonium salicylate. I have found that the bismuth trisalicylate sigoocc nprn cennbt exist in reality, but that it is possible to produce a disalicylate besides the monosalicylate already known and the one and one-halt fold salicylate. When the normal bismuth. salts mineral acids-for instance,

the bismuth nitrate-are caused to act on sodium salicylatc, the bismuth trisalicylate is not obtained, as might be expected; but in consequence of the obvious impossibility of the existence of this salt a m xture of bisninth disalicylate, with tree salicylic acid, is

obtained, from which the bismuth disalicylate may be produced in pure state if the sali cylic acid is removed by extracting it by indifferent dissolving agents or by means of careful neutralization. it, however, removing of. the salicylic acid by boiling with water is tried, the final product obtained is not his inuth disalicylate, but bismuth monosalicylate.

Example: Nine hundred and seventy parts of crystallized bismuth nitrate are brought together with an aqueous solution of one thousand and fifty parts of salicylatc of sodium. After having stirred or trituratedtlie mass for several hours a diluted aqueous solution of ammoniais added until the sour reaction. has just disappeared. After filtering the residue is Washed several times with cold Water and dried at ordinary or only moderately-raised temperature. Instead of di e solving the free salicylic acid with ammonia the raw product of reaction maybe filtered and deprived of free salicylic acid by. extracting agents, such as alcohol, ether, chloroform. As when heated the disalicylate is decomposed by water and alcohol, the we traction in the cold is preferable. The bismuth disalicylate thus obtained is a white powder which contains two molecules of salicyllo acid combined With one atom of blS- n nth, corresponding to the formula An extract prepared with cold Water has a neutral i'eaction which proves that the rodwiltcontains no free salicylic acid.

()0 d alcohol or ether do not split off salicylic acid from the salt. When. boiled with Water or treated with. hot a ueous alcohol, half of the salicylic acid is split off from the salt under formation-of the known bismuth monosalicylate;

For therapeutieal use tlie'new salt has especially two advantages: Fi st, it contains 'more salicylic ecid' second, half of its salicylio acid is splitoll very easily.

Elsi/ling new particulerlydescribed and ascertained theneiture this invention amino. 7

ceases What manner the same is to be performed, I declare that What I claim is- 1. The manufacture of bismuth disalicylate which consists in causing a normalv bismuth salt to act on a solution eia salicylic salt, the base of which forms a soluble salt with the acid of the bismuth salt, and in re- .moving the free salicylic acid from the proiinot of reaction by neutralization or extraction with iiiilili'erent solvents at atempela ture at which the bismuth disalicylate is not yet split up into salicylic acid and bismuth monosalicyiate, substantially as and for the purpose specified.

2. As a new article of manufacture the new salt, bismuth disalic late, a chemical combination of one atom o bismuth with twomole cules of salioylic acid, forming a whitish pow tier of neutral reaction, which is split up into free salicylic acid and bismuth monosslicyi ate by boiling water, substantially as and tor the purposespcciiiei In testimony that ,I claim theforegoing as my inventionl have signed my name, in I'esence' of two witnesses, this 26th day of beptember, 1905.

BRUNO RICHARD SElFEil'i. Witnesses:

PAUL E. Souimime, iAUL Alums; 

